On the use of structured time-series to detect and test hypotheses about within-lakes relationships

1995 ◽  
Vol 52 (4) ◽  
pp. 799-803 ◽  
Author(s):  
Yves T. Prairie ◽  
C. Tara Marshall
Keyword(s):  
Time Series ◽  
Empirical Data ◽  
Single System ◽  
Empirical Relationships ◽  
Cross Sectional ◽  
Apparent Relationship ◽  
Field Season ◽  
The Relationship ◽  
Over Time ◽  
Chlorophyll Concentrations

Aquatic scientists using empirical relationships developed from point measurements or averages from different lakes often assume that these relationships also apply to individual lakes over time. However, this assumption is difficult to test because the extent of variation within a single system is generally much smaller and the relationship accordingly less defined than across a number of systems. We present a new method to extract empirical relationships from the internal structure of a time-series within a single lake. When we applied the method to an extreme simulation, we were able to recover accurately the parameters of the relationship in spite of the absence of any apparent relationship between the variables. When applied to empirical data for phosphorus and chlorophyll concentrations collected daily over one field season, the estimated structural relationship was nearly identical to that estimated from cross-sectional data even though the empirical trend appeared much shallower and very weak.

Cross-Sectional Research Designs in Criminology and Criminal Justice

Criminology ◽  
2020 ◽  
Author(s):  
James V. Ray
Keyword(s):  
Criminal Justice ◽  
Temporal Order ◽  
Longitudinal Research ◽  
Criminal Career ◽  
Individual Change ◽  
Cross Sectional ◽  
Research Designs ◽  
The Relationship ◽  
Criminology And Criminal Justice ◽  
Over Time

Cross-sectional research allows researchers to study a phenomenon or the relationship between variables at one point in time. In cross-sectional research data are collected once for each case (e.g., individual, neighborhood, city, state) at a single point in time. Cross-sectional research is most appropriate for studies that have descriptive or exploratory aims and in many cases are inadequate to assess causal processes due to an inability for researchers to establish temporal order—a necessary but not sufficient condition for causality. However, in some cases cross-sectional research may be adequate or even preferable to assess mediational models such as when the mediator variable is contemporaneous. Due to the nature of cross-sectional research, it is also not possible to utilize this approach to examine patterns or within-individual change in behavior over time. Alternatively, longitudinal designs typically follow the same cases over time and make observations (e.g., surveys, interviews) for each case at multiple time points. This approach allows for researchers to establish temporal order and assess both between and within-individual change over time. There is an ongoing debate among criminologists, particularly those interested in developmental processes and theories, regarding the worth of cross-sectional designs over longitudinal designs. This debate largely stems from the relationship between age and crime in what is typically referred to as the age-crime curve and the criminal career paradigm. That is, traditional cross-sectional research has found that crime peaks in mid- to late adolescence and then gradually declines across adult age groups. Despite the criticisms waged against cross-sectional research and the benefits of longitudinal research to establish temporal order, cross-sectional research designs still dominate criminology and criminal justice research. This may be due to some of the advantages of cross-sectional research and disadvantages of longitudinal research. For instance, cross-sectional research is relatively quick and affordable to carry out, making it a fairly accessible research design to conduct without funding and enables production of timely findings. Most importantly, researchers have developed unique methods of data collection and statistical analyses to overcome concerns of causality in cross-sectional research including retrospective or life history analyses, experimental survey designs, and repeated cross-sections or trend data. While these “fixes” do not allow researchers to assess within-individual change in outcomes (e.g., behaviors, attitudes, personality), they do address issues of temporal order and nonspuriousness within the cross-sectional design. The following article presents works that address various aspects of cross-sectional research and some examples of research utilizing this design.

scholarly journals Comparing Dynamic Pies: A Strategy for Modeling Compositional Variables in Time and Space

2017 ◽  
Vol 7 (3) ◽  
pp. 523-540 ◽  
Author(s):  
Christine S. Lipsmeyer ◽  
Andrew Q. Philips ◽  
Amanda Rutherford ◽  
Guy D. Whitten
Keyword(s):  
Time Series ◽  
Political Science ◽  
Recent Work ◽  
Spatial Relationships ◽  
Contextual Variables ◽  
Cross Sectional ◽  
Us States ◽  
The Us ◽  
Dependent Variables ◽  
Over Time

Across a broad range of fields in political science, there are many theoretically interesting dependent variables that can be characterized as compositions. We build on recent work that has developed strategies for modeling variation in such variables over time by extending them to models of time series cross-sectional data. We discuss how researchers can incorporate the influence of contextual variables and spatial relationships into such models. To demonstrate the utility of our proposed strategies, we present a methodological illustration using an analysis of budgetary expenditures in the US states.

Human Capital as a Fertility Determinant in an Economically Developed Homogeneous Population

1982 ◽  
Vol 3 (2) ◽  
pp. 217-231
Author(s):  
ANN SCHWARZ-MILLER
Keyword(s):  
Human Capital ◽  
West Germany ◽  
Empirical Relationships ◽  
Cross Sectional ◽  
Homogeneous Population ◽  
Regression Techniques ◽  
Desired Family Size ◽  
The Impact ◽  
The Relationship ◽  
General Time

This study analyzes the relationship between human capital and fertility in West Germany, an economically developed homogeneous society that has been characterized by low and declining birthrates, a rise in educational levels, and increasing female labor force participation for more than a decade and a half. The theoretical links between human capital and fertility are first explored within the framework of an informal household optimization model drawn from the economics of fertility literature. Cross-sectional empirical relationships are then assessed using OLS regression techniques. The impact of educational measures on desired family size is found to be statistically weaker than in prior studies. Evidence is presented for the existence of a general time trend in tastes as a source of falling fertility. It is argued that these results may stem from the existence of strong norms and other special characteristics of the society, casting doubt on the validity of the economic model in such a setting.

Self-reported school demands and psychosomatic problems among adolescents – changes in the association between 1988 and 2011?

2017 ◽  
Vol 47 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Karina Nygren ◽  
Curt Hagquist
Keyword(s):  
Multinomial Logistic Regression ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Student Groups ◽  
Individual Level ◽  
Psychosomatic Problems ◽  
Data Collections ◽  
The Impact ◽  
The Relationship ◽  
Over Time

Aims: The aim of the present study was to examine changes over time in the relationship between self-reported school demands and psychosomatic problems, also considering the impact of student influence and teacher support. Methods: Data from a cross-sectional study (Young in Värmland) including eight data collections (1988–2011) among Swedish students aged 15–16 were used ( n = 20,115). Analyses with multinomial logistic regression and descriptive statistics were applied. Results: Between 1988 and 2011, the proportions of students with a higher degree of psychosomatic problems increased, as did the proportion of students experiencing school demands that were too high. Finer-level analyses based on stratification of student groups did not show any associations at the aggregated level between increases of school demands and psychosomatic problems. Similarly, individual level analyses showed that the strength of the association between school demands and psychosomatic problems was not affected by year of investigation. Conclusions: Changes in school demands over time could not explain the increasing trend in psychosomatic problems among adolescents. Since the relationship between school demands and psychosomatic problems is strong across time, there is, however, a continued need for school-based interventions. More studies are required to gain further understanding of adolescent mental health from a trend perspective.

scholarly journals VISUAL IMPAIRMENT AND ENGAGEMENT IN COGNITIVELY STIMULATING ACTIVITIES

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S656-S656
Author(s):  
Bonnielin Swenor ◽  
beatriz Munoz ◽  
Eleanor M Simonsick
Keyword(s):  
Visual Acuity ◽  
Visual Impairment ◽  
Significant Decline ◽  
Cross Sectional ◽  
Impaired Group ◽  
Cognitive Activities ◽  
Using Data ◽  
The Relationship ◽  
Stereo Acuity ◽  
Over Time

Abstract We examined the relationship between visual impairment (VI) and engagement in cognitively stimulating activities using data from 924 participants in the Cognitive Vitality Sub-Study of the Health ABC Study. At Year 3 (baseline for these analyses), vision was assessed as: visual acuity (VA), contrast sensitivity (CS), and stereo acuity (SA). Participation in cognitively stimulating activities was determined based on responses to 12 questions (administered at Years 3, 5, 7, and 9) assessing frequency of participation ranging from none to daily. We calculated the total number of activities engaged in at least monthly. In cross-sectional analyses adjusted for age, race, and sex, impaired VA (≤20/40, 8%), CS (<1.55, 5%), and SA (<80 secs arc, 29%) was associated with participation in fewer cognitive activities (β=-0.54, 95% CI:-1.06, -0.03; β=-0.59, 95% CI:-0.12, 0.06; β=-0.40, 95% CI:-0.81, -0.18, respectively). Longitudinally, change per year in the number of activities differed by baseline participation levels. Those participating in ≥5 activities at baseline (population median) had a significant decline in the number of activities, irrespective of VI status. However, for those participating in <5 activities at baseline, the increase in these activities tended to be lesser in the VI than in non-VI groups, and for SA this increase was significantly lower for the impaired group (βimpaired=0.004; 95% CI:-0.05, 0.05; βnot-impaired=0.06; 95% CI: 0.03, 0.10; time x SA interaction p=0.0496). These data indicate that older adults with VI participate in fewer cognitive activities and the change in participation over time differs from than those without VI.

scholarly journals GARY BECKER ON THE QUANTITY AND QUALITY OF CHILDREN

2015 ◽  
Vol 81 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Matthias Doepke
Keyword(s):  
Economic Analysis ◽  
Family Income ◽  
Industrialized Countries ◽  
Cross Sectional ◽  
Fertility Choice ◽  
The Poor ◽  
Gary Becker ◽  
The Relationship ◽  
Over Time

Before Gary Becker, fertility choice was widely considered to be outside the realm of economic analysis. Apart from intellectual tradition, one reason for this was that the data on fertility did not immediately suggest an economic mechanism. In industrialized countries, fertility had declined strongly over time, even though family incomes were rising. Similarly, in many studies using cross-sectional data the relationship between family income and fertility had been shown to be either flat or declining. To many observers, these observations suggested that the “taste” for children had waned over time and that high income families placed less value on childbearing than the poor.

The Establishment of the Mode for Price Fluctuation of Financial Market and the Prediction of its Tendency

2013 ◽  
Vol 401-403 ◽  
pp. 1444-1448
Author(s):  
Yan Ying Gao ◽  
Na Lv
Keyword(s):  
Time Series ◽  
Financial Crisis ◽  
Financial Market ◽  
Empirical Data ◽  
Statistical Properties ◽  
Price Fluctuation ◽  
Financial Instrument ◽  
Lehman Brothers ◽  
One Step ◽  
Over Time

The financial world is an uncertain universe where events take place every day, every hour, and every second. Information arrives completely randomly and so do the events. The operations in business activities are continually affected by these events beyond the control of the management. One of the most significant examples in financial economics is the most recent economic-financial crisis of 2008-2009 caused by the collapse of Lehman Brothers Holdings Inc.. The aim of this study is to investigate the statistical properties of the empirical data based on time series of the RFTSE100, RS&P500 and forecast one-step-ahead returns for three months. Additionally, we study the behavior of volatility, which is currently determined as a measure for variation of price or return of a financial instrument over time.

scholarly journals The Validity of the Enns and Koch, and Berry et al. Measures of State Policy Mood: Continuing the Debate

2021 ◽  
pp. 1-12
Author(s):  
William D. Berry ◽  
Richard C. Fording ◽  
Russell L. Hanson ◽  
Justin K. Crofoot
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Empirical Evidence ◽  
State Policy ◽  
Face Validity ◽  
The South ◽  
Cross Sectional ◽  
Series Analysis ◽  
Statistical Results ◽  
Over Time

Abstract Enns and Koch question the validity of the Berry, Ringquist, Fording, and Hanson measure of state policy mood and defend the validity of the Enns and Koch measure on two grounds. First, they claim policy mood has become more conservative in the South over time; we present empirical evidence to the contrary: policy mood became more liberal in the South between 1980 and 2010. Second, Enns and Koch argue that an indicator’s lack of face validity in cross-sectional comparisons is irrelevant when judging the measure’s suitability in the most common form of pooled cross-sectional time-series analysis. We show their argument is logically flawed, except under highly improbable circumstances. We also demonstrate, by replicating several published studies, that statistical results about the effect of state policy mood can vary dramatically depending on which of the two mood measures is used, making clear that a researcher’s measurement choice can be highly consequential.

scholarly journals Network analysis of firearm movement among US states

2020 ◽  
Author(s):  
Sae Takada ◽  
Kristen Choi ◽  
Shaw Natsui ◽  
Altaf Saadi ◽  
Liza Buchbinder ◽  
...  
Keyword(s):  
Time Series ◽  
Network Analysis ◽  
Negative Binomial ◽  
State Level ◽  
Negative Binomial Regression ◽  
Similar Model ◽  
Cross Sectional ◽  
Us States ◽  
Binomial Regression ◽  
The Relationship

Abstract Background: The movement of firearm across state lines may decrease the effectiveness of state-level firearm laws. Yet how state-level firearm policies affect cross-state movement have not yet been widely explored. This study aims to characterize the interstate movement of firearms and its relationship with state-level firearm policies. Methods: Cross-sectional time series network analysis of interstate firearm movement using Bureau of Alcohol, Tobacco, Firearms, and Explosives firearm trace data (2010 -2017). We constructed the network of firearm movement between 50 states. We used zero-inflated negative binomial regression to estimate the relationship between the number of a state’s firearm laws and number of states for which it was the source of 100 or more firearms, adjusting for state characteristics. We used a similar model to examine the relationship between firearm laws and the number of states for which a given state was the destination of 100 or more firearms.Results: Over the 8-year period, states had an average of 26 (SD 25.2) firearm laws. On average, a state was the source of 100 or more crime-related firearms for 2.2 (SD 2.7) states and was the destination of 100 or more crime-related firearms for 2.2 (SD 3.4) states. Greater number of firearm laws was associated with states being the source of 100 or more firearms to fewer states (IRR0.67 per SD, p<0.001), higher odds of not being a source to any states (aOR1.56 per SD, p<0.001), and states being the destination of 100 or more firearms from more states (IRR1.83 per SD, p<0.001).Conclusions: Restrictive firearm policies are associated with less movement of firearms to other states, but with more movement of firearms from outside states. The effectiveness of state-level firearm-restricting laws is complicated by a network of interstate firearm movement.

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